support cpu idle and burst for cgroupv2

cgroup2/cpu.go

@@ -34,6 +34,8 @@ func NewCPUMax(quota *int64, period *uint64) CPUMax {
 
 type CPU struct {
 	Weight *uint64
+	Idle   *uint64
+	Burst  *uint64
 	Max    CPUMax
 	Cpus   string
 	Mems   string
@@ -61,12 +63,24 @@ func (r *CPU) Values() (o []Value) {
 			value:    *r.Weight,
 		})
 	}
+	if r.Idle != nil {
+		o = append(o, Value{
+			filename: "cpu.idle",
+			value:    *r.Idle,
+		})
+	}
 	if r.Max != "" {
 		o = append(o, Value{
 			filename: "cpu.max",
 			value:    r.Max,
 		})
 	}
+	if r.Burst != nil {
+		o = append(o, Value{
+			filename: "cpu.max.burst",
+			value:    *r.Burst,
+		})
+	}
 	if r.Cpus != "" {
 		o = append(o, Value{
 			filename: "cpuset.cpus",

cgroup2/cpuv2_test.go

@@ -35,11 +35,14 @@ func TestCgroupv2CpuStats(t *testing.T) {
 		quota  int64  = 10000
 		period uint64 = 8000
 		weight uint64 = 100
+		// The burst in the range [0, $quota].
+		burst uint64 = 1000
 	)
 
 	c, err := NewManager(defaultCgroup2Path, groupPath, &Resources{
 		CPU: &CPU{
 			Weight: &weight,
+			Burst:  &burst,
 			Max:    NewCPUMax(&quota, &period),
 			Cpus:   "0",
 			Mems:   "0",
@@ -51,11 +54,34 @@ func TestCgroupv2CpuStats(t *testing.T) {
 	})
 
 	checkFileContent(t, c.path, "cpu.weight", strconv.FormatUint(weight, 10))
+	checkFileContent(t, c.path, "cpu.max.burst", strconv.FormatUint(burst, 10))
 	checkFileContent(t, c.path, "cpu.max", "10000 8000")
 	checkFileContent(t, c.path, "cpuset.cpus", "0")
 	checkFileContent(t, c.path, "cpuset.mems", "0")
 }
 
+func TestCgroupv2CpuIdle(t *testing.T) {
+	checkCgroupMode(t)
+	group := "/cpu-test-cg-idle"
+	groupPath := fmt.Sprintf("%s-%d", group, os.Getpid())
+	var (
+		idle uint64 = 1
+	)
+	res := Resources{
+		CPU: &CPU{
+			Idle: &idle,
+		},
+	}
+	c, err := NewManager(defaultCgroup2Path, groupPath, &res)
+	require.NoError(t, err, "failed to init new cgroup manager")
+	t.Cleanup(func() {
+		os.Remove(c.path)
+	})
+
+	checkFileContent(t, c.path, "cpu.weight", "0")
+	checkFileContent(t, c.path, "cpu.idle", "1")
+}
+
 func TestSystemdCgroupCpuController(t *testing.T) {
 	checkCgroupMode(t)
 	group := fmt.Sprintf("testing-cpu-%d.scope", os.Getpid())

cgroup2/manager.go

@@ -869,9 +869,20 @@ func NewSystemd(slice, group string, pid int, resources *Resources) (*Manager, e
 			newSystemdProperty("MemoryMax", uint64(*resources.Memory.Max)))
 	}
 
-	if resources.CPU != nil && resources.CPU.Weight != nil && *resources.CPU.Weight != 0 {
-		properties = append(properties,
-			newSystemdProperty("CPUWeight", *resources.CPU.Weight))
+	if resources.CPU != nil {
+		// Systemd v252 added support for setting cgroup v2 cpu.idle in systemd/systemd#23299
+		// The way it works is
+		// if CPUWeight == 0, cpu.idle is set to 1;
+		// if CPUWeight != 0, cpu.idle is set to 0.
+		// Do not add duplicate CPUWeight property
+		if resources.CPU.Idle != nil && resources.CPU.Weight != nil && *resources.CPU.Weight != 0 {
+			properties = append(properties,
+				newSystemdProperty("CPUWeight", uint64(0)))
+		}
+		if resources.CPU.Weight != nil && *resources.CPU.Weight != 0 {
+			properties = append(properties,
+				newSystemdProperty("CPUWeight", *resources.CPU.Weight))
+		}
 	}
 
 	if resources.CPU != nil && resources.CPU.Max != "" {